Coeliac Disease in Children

Overview

Coeliac disease is an autoimmune systemic disorder primarily affecting the small intestine. It is provoked by gluten in susceptible individuals and can lead to malabsorption. Gluten is a protein found in wheat, barley, and rye.

Its pathophysiology is not entirely known and it is thought that its aetiology is multifactorial, including genetic and environmental factors.

Epidemiology

• Coeliac disease may have an incidence rate of around 14 per 100,000 per year
• Its incidence has 2 peaks; one shortly after weaning with gluten in the first 2 years of life, and the other in adolescence to 30 years

Risk Factors

• Family history
• Immunoglobulin A (IgA) deficiency
• Type 1 diabetes
• Autoimmune liver disease
• Autoimmune thyroid disease
• Human leukocyte antigen (HLA)-DQ2 and HLA-DQ8

Presentation

The onset of symptoms may coincide with the introduction of gluten-containing foods (such as weaning):

• Failure to thrive
• Diarrhoea
• Fatigue
• Other features of malabsorption:
  • Steatorrhoea
  • Anaemia – may be iron-deficiency anaemia or anaemia secondary to B12/folate deficiency
  • Metabolic bone disorders (e.g. osteomalacia, osteopenia, or osteoporosis) and fragility fractures due to malabsorption of calcium and vitamin D
• Mouth ulcers that may be persistent or severe

Investigations

• Coeliac serology testing – used as screening:
  • Only valid if patients continue to eat gluten for a minimum of 6 weeks before testing
  • This does not diagnose coeliac disease. It is used to decide whether further assessment is necessary
  • 1^st-line: serum IgA tissue transglutaminase antibody (tTGA) + total IgA
    • Total IgA is measured because, in some individuals with an IgA deficiency, this may return a negative result
  • 2^nd-line: IgA endomysial antibody (EMA) if IgA tTGA is unavailable
  • Consider re-testing if a person presents with new symptoms of coeliac disease, despite previous serology
• Referral to gastroenterology and endoscopic intestinal biopsy:
  • The gold standard diagnostic test
  • Biopsies are generally done in the duodenum and jejunum
  • Findings suggesting coeliac disease are:
    • Crypt hyperplasia
    • Villous atrophy
    • Intraepithelial lymphocytosis
    • Infiltration of the lamina propria with lymphocytes

Other investigations

• Type 1 diabetes autoantibodies:
  • There is frequent overlap between coeliac disease and type 1 diabetes mellitus

Management

Overview

• 1^st-line: lifelong gluten-free diet
• Monitoring with IgA tTGA or IgA EMA may be considered to assess compliance
• Offer annual influenza vaccine and 5-yearly pneumococcal vaccine:
  • Around 1/3 of patients with coeliac disease have hyposplenism, predisposing them to pneumococcal infection. This is thought to be due to functional hyposplenism and splenic atrophy

Patient Advice

• Foods that contain gluten include:
  • Those based on wheat, barley, or rye
  • Those that may be contaminated with gluten
  • Those that contain malt, including beer
• Alternatives sources of starch that may be eaten include:
  • Rice
  • Potatoes
  • Corn

Complications

• Anaemia:
  • Secondary to malabsorption of iron, B12, and folate 
• Failure to thrive and delayed puberty:
  • Secondary to malabsorption
• Hyposplenism:
  • Due to functional hyposplenism and splenic atrophy
  • Seen in 1/3 of patients with coeliac disease
• Metabolic bone disease – osteomalacia, osteopenia, or osteoporosis:
  • Due to malabsorption of vitamin D and calcium
• Lactose intolerance:
  • Due to bowel damage due to inflammation
• Malignancy:
  • Such as Hodgkin’s and non-Hodgkin’s lymphomas, such as enteropathy-associated T-cell lymphoma (EATL), bowel adenocarcinoma, and pancreatic cancer 
• Problems with pregnancy:
  • Including subfertility and recurrent miscarriage
• Refractory coeliac disease:
  • Rare and seen in around 1% of cases
  • Where symptoms and villous atrophy persist despite avoiding gluten
• Reduced quality of life:
  • Due to coeliac disease itself and the social implications of adhering to a gluten-free diet
• Psychiatric problems:
  • Including depression, anxiety, and eating disorders

Prognosis

• The resolution of symptoms and degree of duodenal recovery do not correlate
• Most patients have a complete solution of symptoms on a gluten-free diet alone
• Symptoms tend to improve within weeks of starting a gluten-free diet, however, it can take up to 2 years for the gastrointestinal tract to recover